Ink
by Red Bess Rackham
Summary: Ruby always knew the whole soulmate thing was total bull—she died without one and became a demon. But things get super complicated when she ends up getting one after all, in the middle of trying to stop Lillith from bringing on the apocalypse. Worse: he's an angel. Literally. (Oneshot) (Ruby/Cas, Soulmate AU, for RarePairFest 2017)


_A/n: [Originally written for RarePairFest 2017, in August] My dear recipient OhWilloTheWisp, I very much wanted to write you something 'Pushing Daisies', but after weeks of struggle, I simply could not come up with anything. I switched tracks and did something 'Supernatural' instead. It has genuinely been ages since I rewatched season 4 and I've never written Ruby, nor a Soulmate AU before. So I hope this is okay and what you were looking for with your prompts. :) Enjoy!_

* * *

 **Ink**

The whole soulmate schtick was bullshit.

Every single person on the damn planet was supposed to get one before they died—have their name appear on your wrist in bright, colorful ink when you met them. Yet Ruby died and went to Hell soulmate-less. She gave up on the concept pretty freaking quick after that—nobody finds a soulmate in Hell.

She'd spent a couple centuries or so down in the pit, her humanity scraped out of her, little by little. Then she wound up topside as a demon in a meatsuit, running errands for higher demons. _That_ was bullshit too, but at least it gave her the chance to bide her time until something better came along.

Turns out "better" was actually caring about what happened to the planet and the people on it.

Ruby watched stupid humans find their stupid soulmates, going all heart-eyes and weak-kneed, and living happily ever after. She saw them living, connecting, loving. At first, she rolled her eyes. Maybe once upon a time she was jealous of that kind of thing, but now it looked shallow and ridiculous. Meaningless. A lifetime or two of having her skin peeled off her body could do that, she supposed.

Despite those eons in the pit, something clung to her, deep inside. Some insane notion that what Azazel wanted and what Lillith wanted was wrong. That bringing the apocalypse down on all these oblivious morons tracking their away across the planet in search of bliss was a waste, though Ruby could never put her finger on why.

That was probably what led her to the Winchesters in the first place. Her search for figuring out why she, of any demon, remembered being human. Why she cared. Why she wanted to make a difference. And hey, so did the Winchesters.

They were a couple of hunters too busy fighting the good fight to bother with all the soulmate crap, but they saved lives and were number one on Lillith's hit list. Their attitude was honestly kind of refreshing, and it gave her a wicked sense of glee to go behind the Lillith's back. So Ruby wormed her way into their lives and she gave them her dagger and she fought monsters and demons alongside them.

Sometimes things got a little dicey—the boys had some _serious_ trust issues—and because fate was a bitch, she got sent back to the pit for some more good old fashioned torture. Turns out Lillith knew more than she let on after all, and Ruby was thoroughly punished for helping the wrong side.

So a few thousand _yes mistress whatever you say mistress_ and lashings later, Ruby came up for air and found a new meatsuit. She squared her shoulders, admiring the body in the hospital room's mirror. It was curvier, smoother, and softer than the last one. Brunette, instead of blonde. It made her feel softer, in a way, but not in a bad way—she just wasn't all hard edges and blistering sarcasm anymore. One thing that hadn't changed: she was as determined as ever to put an end to Lillith and her evil plans.

As Ruby threw on some clothes, she paused to smirk at this body's empty wrist—this one had died without a soulmate, too.

 _See? Bullshit_.

She marched out of her hospital room. As she passed by the ER, she heard some nurse burst into screeching exclamations over the patient brought in by ambulance. Ruby spared them a glance, watching the nurse compare shining tattoos with the toothy, broken-limbed victim.

It was pathetic and saccharine, but that thread of humanity still impossibly holding her together twanged. Their joy reached out to her, reminded her that despite everything, she _still_ remembered how it was to be human.

She hated that feeling, yet she clung to it at the same time. That sense of remembering love and faith and friendship flickered deep in the blackness of her being—a sputtering flame that never went out, no matter what she or anyone else did to douse it.

Ruby was a demon, intent to do something good and just, and there was no greater contradiction on the planet.

She couldn't help wanting to save people, even if she ground her teeth together and was briefly tempted to torch the hospital on her way out (people were still oblivious idiots too focused on the soulmate crap, after all). But some sort of longing for peace and connection drove her on, echoing across the centuries to and from a girl who died too young. People deserved to find each other, Ruby thought, and they deserved to live, and not turn to ash in a fiery apocalypse.

Even if they were moronic assholes.

Ruby pushed out into the night, sucking in a breath of chilly air, and stole the nearest hunk of junk she could find. Sam was probably wondering if she'd ever come back to him.

Ruby staggered back, wiping the blood from her lips. These demons were seriously pissing her off.

She drove her knife forward in a wide arc, catching Magnus across the face. He bellowed and reeled away from her, sparking and smoking. He collided with the couch in the old living room, buckling to his knees. Ruby grinned.

"If you're gonna ambush a girl, you gotta try a little harder next time," she said with an arrogant twirl of her blade. She side-stepped the shattered coffee table.

The other three demons charged forward. Ruby blocked the first few blows, then ducked and spun. She stabbed in and out with her knife, catching one demon in the gut and landing shallow cuts on the other two. They yowled and punched wildly, trying to slow her down.

Ruby grunted when a fist connected with her head, sending her sprawling onto her back. She kicked out blindly, cursing. Of course, the _one_ time she decided to go hunting for leads without Sam was the moment Lilith picked to send a little pack to take her out. The dead vamp in the kitchen was _so_ not worth fighting off four mid-level demons.

She rolled behind the tattered recliner, narrowly avoiding the dining chair that was launched her way. It exploded against the dusty wall and one of the demons descended on her. She drove her blade up at him. The knife plunged into his throat and he flickered with orange light before collapsing to the side. Ruby pushed him off her and hopped to her feet, ready to take on the last two demons. They snarled and spat blood.

That was about when the whole place started going haywire, lights blazing on, popping and exploding in a shower of sparks. The demons spun, confused and scared. Ruby shielded her eyes and backed up as the cobwebbed chandelier crackled and burst apart.

 _What new hell is this?_

The ground shook, brilliance filled the room, and two of the remaining demons smoked out, heading for the hills. Apparently risking Lillith's wrath was a better option than facing whatever was making the earth shiver under her boots. Ruby hesitated—she didn't want to lose her own meatsuit, and if her enemies were running, surely that meant the new player was an ally?

When the walls stopped rattling and the light faded to reasonable level, Ruby lowered her hand. Her lips parted in shock. In the middle of the room stood a man with brown hair, crystalline blue eyes, a beige trenchcoat, and the shadows of _angel wings_. It'd been years since she'd laid eyes on an actual angel—the apocalypse must've been heating up more than she thought, if the big man upstairs was sending his best and brightest down to—

"Ow!" she shrieked. Red hot pain sliced up her arm. She smacked her hand onto her wrist where it stung the most, searing like a brand. Ruby cursed loudly and rocked on the spot. What the hell was he _doing_ to her?

Tears blurred her vision and she blinked them back, dropping a few more colorful words. Finally the pain receded. She held her wrist a second longer as belated panic spiked through her.

 _No. No freaking way._

Ruby froze, afraid to look. It was supposed to be a good feeling—if it was what she thought it was, which it wasn't, because it _couldn't_ be for so many hundreds of reasons. What she'd just experienced had been anything but good. And it was not, it could _not_ be...

Hand still clutching her other wrist, Ruby forced herself to look up at the angel. _No, no, no._

He was doubled over, holding his goddamn wrist.

She shakily lifted her fingers, dread pumping through her like adrenaline. There, etched on her inflamed skin in black letters, was a name. His name.

 _Castiel_.

"Fuck," she spat.

The angel—Castiel—looked up, chest heaving. "Are you...Ruby?"

Before she threw up, Ruby ran from the room.

Back at the motel, Ruby tore one of her shirts to ribbons and wrapped a couple strips like bandages around her prickling wrist. It still throbbed, like the mark was wrong on a cellular level, and her fingers fumbled with the cloth.

Covering the name seemed like the only sane option—it wasn't shining and colorful, it wasn't wonderful, it was the name of an _angel_ and she was a _demon_. Something, somewhere had gone hideously awry, so yeah. Covering it was good.

Ruby sunk onto the edge of the bed and buried her face in her hands. She had no idea what to do. She'd never once heard of a demon getting a soulmate—this was completely uncharted territory, and she wanted nothing to do with it.

She'd come topside to counter an apocalypse, not find a damn soulmate, which she shouldn't have been capable of having in the first place. Maybe, technically, she was on the same fighting side as the angel, but _shit_ , he could so _not_ be her soulmate.

The walls thrummed and Ruby jumped to her feet. The bastard had followed her. She leapt for her knife, which she'd discarded near the pillow when she'd been panic-pacing earlier. She brandished it and waited.

At the knock on the door, Ruby tightened her grip on her knife. It killed demons, but she didn't know about angels. Now was as good a time as any time find out, she figured.

She glanced at the open window. _Then again_ … Maybe she should smoke out, find another meatsuit, explain to Sam—

"Please," came a deep voice from the other side of the door. "Ruby...please let me in."

Ruby swallowed. The voice tugged at her. She instinctively shoved it away, but the _feel_ of it lingered, soothing and safe in a way she'd never experienced in her life—any life. That thread of humanity ached, longed for that voice.

She clenched her teeth together, frozen with indecision and hating herself for it.

The doorknob turned and the door edged open, revealing the face of the angel Castiel. His human features were cautious and hopeful, though the angelic ones beneath were ancient and too bright to look at straight on. She wondered if the sight of her demon features beneath her human ones were turning his stomach the way his grace was turning hers.

He held up a placating hand. "I apologize for intruding," he said. He slowly rotated his arm so she could her name, signed eternally black on his wrist. "But you fled before we had a moment to discuss our situation."

"And what situation is that, exactly?" Being obtuse on purpose seemed like a good way to bide some time to figure out what the hell she should even begin to say.

Castiel gently closed the door. "To my knowledge, this has never happened before."

"Good to know," she mumbled, though she still didn't lower her knife. Emotion warred in her gut—she didn't know whether to be relieved that she wasn't alone in this, glad the soulmate crap was real for her after all, or pissed that it was some freaking angel.

"I am not going to hurt you," Castiel said, taking a few steps closer but stopping when she backed up. "I used the door so I would not frighten you."

"I'm apparently soulmates with an angel—I'm way beyond frightened," Ruby snapped.

He frowned. "How do you think this is for me? _My_ soulmate is a demon." Disgust dripped from his voice.

"Lucky you," she quipped, and his frown only deepened.

"We should discuss this," said Castiel. "We must decide how to proceed."

"Discuss what? There's nothing—I'm not getting with you, you're not getting with me, we're not friends, never will be. Neither of us are human and therefore not bound by stupid human laws and rituals."

Ruby let her knife come down, but she stayed ready. Angels were generally assholes and she wouldn't past him to smite her just so he didn't have to deal with her anymore.

"There's nothing to talk about," she continued. "You go live your life in Heaven, doing whatever it is you angels do, and I'll be on my way. No harm, no foul. And we never have to see each other again."

"An event as unprecedented as this should be analyzed carefully," Castiel stated. "There must be a logical explanation for why this has occurred."

Ruby shrugged. "Maybe the dead girl I'm wearing was supposed to be your meatsuit's soulmate and we're caught in the crossfire."

It wasn't a bad theory, she decided. It made a hell of a lot more sense than her and Castiel.

He shook his head again. "That's not how it works."

"Really? Are you an expert on soulmates?" Ruby scoffed. "It's also supposed to feel good and be lovely and magical. All I felt was fire and pain. How was it for you? Was I good?"

In typical angel fashion, her tone soared right over his haloed head. "I experienced severe discomfort as well." He itched at the offending ink on his wrist.

"There you go. Something went wrong and I vote we ignore it, since there's no way to fix it." Ruby waved her hand at him and sheathed her knife, downgrading him from Likely Threat to Just Annoyed.

Castiel's brows pinched together. He couldn't seem to come up with a suitable response.

Ruby made a shooing motion and after several seconds of uncertain fussing, Castiel slumped to the door. He paused on the threshold, reaching for her.

"Ruby, I…"

"Catch you never, Castiel," she said, and kicked the door shut, not caring if she hit his outstretched arm.

She had to take a moment to slow her breathing before she got packing her things—she could've sworn she saw her name on his wrist flash pleasantly red.

Of course, because the universe was determined to screw her every which way it could at this point, the damn angel got himself tangled up with the Winchesters. Of course, so was she. So of _course_ , she couldn't freaking get away from him as they teamed up to stop the apocalypse with Sam and Dean.

Being in the same room as Castiel sucked. Her blood hummed in her veins and she had to actively stop herself from admiring him—the curve of his pink lips, the line of his jaw, the blue of his eyes that shifted tones in different lights. He radiated strength, and the grace that had initially been blinding and made her skin crawl, now coated her with an alien sense of security and comfort. She caught herself wondering what it'd feel like to have his arms wrap around her and shoved the urge away.

Ruby tore her gaze from him and focused on cleaning the array of weapons on the table. She went over the plan for raiding the demon nest in her head—one more step to ganking Lillith—and she didn't look up when she felt his eyes on her. Her cheeks flooded with warmth and she hated her human flesh for giving her away, for being so damn weak.

She blurted something about needing supplies and all but bolted from the room. If Sam or Dean thought she was acting weird the past several weeks, they didn't say. Ruby had kept her wrist bandaged and Castiel never took off that stupid trenchcoat. Neither of them had said another word to each other about their "situation" since their first conversation.

Ruby nabbed an old gray Honda and drove well out of town before good ol' Nosy Wings caught up with her. She almost drove off the road when he appeared in the backseat.

"I need to talk to you," he said.

Ruby cursed and steadied the car. "Not while I'm driving!"

"Then find a suitable place to stop driving."

She came to a screeching halt outside a roadside pitstop and he was standing there, annoyingly calm, when she climbed out of the car.

"Why'd you follow me?" she bit out, slamming the car door hard enough to rattle the bumpers.

"I wanted to know where you were going," he replied. "The explanation you gave at the hotel did not seem—"

"Screw off, Castiel." Ruby strode past him towards the grubby, little truck stop restaurant. "I don't want to talk."

"We cannot keep hiding from this." Castiel caught up to her easily, matching her angry strides with long, calm ones. Their feet crunched over the gravel, irritatingly in sync.

"We're doing just fine so far," she growled. Why couldn't he just leave her alone? What was so hard about that? They weren't human, they didn't have to play like they could be.

"Ruby—"

"What?" She stopped and rounded on him. " _What_ , Cas, hmm? What do you really expect can happen here? You think just because the universe branded us as soulmates, just because fate screwed us, we should jump into each other's arms?"

"We should consider the possibility that we are meant to."

She shook her head. "Why?"

Castiel slid his sleeve back and helplessly looked down at his wrist. "Your name appeared here," he murmured. "Not anyone else's, in my centuries of being an angel."

"So what?" Ruby threw her arms up and let them slap down at her sides.

"Don't you question why? Are you not plagued by the reason this has happened, to _us_ , now, at this time?"

"No," she lied, fast and flat. She would never admit to him how much sleep and time and energy the damn tattoo on her wrist had cost her.

Castiel pressed his lips together and covered her name with his sleeve again. "I am an angel of the Lord, yet I am defying my fellow angels to aid humanity. You are, in essence, doing the same. I believe that is why we have been chosen to be linked together."

"It's a cosmic joke," Ruby said, the fight suddenly draining out of her. "Don't you see that yet? Angel, demon. Never the twain shall meet."

Yelling at him was like kicking a puppy. Though that had brought her some sort of savage pleasure at first, now it was just exhausting. He never fought back and she just ended up feeling guilty and hating everything.

"We could unite our kinds," he tried. "Stop this war, and every war here after."

"We couldn't, and you know it. Demons are demons and angels are angels, since the beginning of time. Nothing'll change that."

"But we are the exception to that rule," he insisted.

Ruby hated that earnest expression of his—it made her want to hug him, kiss him, trust him, believe him. It made her want to jump off a bridge because she couldn't _have_ him, no matter what her wrist said.

She waved him off and stormed into the truck stop. Thankfully, he didn't follow.

"Where's your bathroom?" she demanded of the hostess.

Ruby knew something was wrong immediately—the air crackled with the wrong kind of energy for a place full of humans. She snatched up her knife and the hostess' eyes flashed coal black.

"Hey, Ruby," she said, her tone mocking and acidic. "We've been expecting you."

Ruby looked past the bland human features to the writhing, twisted demon below. "Piper. Long time, no kill. How're things in the pit these days? Still licking Alastair's shoes?"

Piper shrugged. "You'll know for yourself in a minute."

Something clanked noisily behind her. Ruby glanced over her shoulder at a pair of burly truckers barring the door. The smattering of patrons in the place stood, black eyes gleaming with malice. Everyone in the place was a demon, ready for a fight.

"How'd you know I'd pull in here?" Ruby asked, flexing her grip on her knife. She was glad she'd taken it back from Dean or she'd have been so much more screwed than she already was right about now.

"We were tracking you," Piper answered matter-of-factly. "We kept up, smoked in when you stopped."

 _Right about when Castiel was distracting me_. She cursed under her breath. That damn angel was about to get her killed. She should never have left the motel.

"Lillith's pretty pissed, you know." Piper smoothed her hands down her perky uniform. "She knows you're working with the Winchesters again, even though you swore service to her, _again_. She knows you've been lying to her."

Ruby couldn't help smirking. "Took her long enough."

Piper advanced slowly, signalling the rest of the demons to close in too. "And what's this I hear about you snagging yourself an angelic soulmate?"

"Fate's a bitch," Ruby retorted, and threw the first punch.

Piper blocked it and drove her fist into Ruby's gut. The other demons closed in. There were several confused seconds where Ruby spun and lashed out and fought as hard as she could—nobody was sending her back to the pit.

Something sliced her arm, one of them kicked her shins. Ruby staggered back, yelping, only to be met with another demon's punch to her back. Ruby growled and spun her knife, stabbing him deep in the gut. She lurched out of the way of another demon, landing the knife blade in his spine as he flew by.

Piper's elbow impacted Ruby's shoulder hard enough that Ruby cried out and crashed to the floor. Ruby rolled and tried to get up, but Piper tackled her.

Then the whole restaurant shone bright white and the walls reverberated hard enough that the windows shattered. Piper managed one more hit to Ruby's face before Castiel's hand grabbed Piper's head from behind. The demon screamed as she burned inside out, and Ruby looked away, grimacing. Castiel shoved the body off of Ruby and looked down at her grimly.

"I didn't...need...saving," Ruby panted. Her shoulder throbbed as she leaned sideways to spit out a mouthful of blood.

"I did not say you did," said Castiel. He held out his hand to help her up, but Ruby glared at it.

All right, so he _did_ save her life and that was great. But she wasn't taking his hand. She wasn't furthering this any more than they already had. She wasn't.

Castiel knelt instead. He reached for her again anyways, this time his fingers closing gently around her forearm. He eased her towards him and Ruby hated... _really liked_ the way her skin zinged and tingled at his touch. She gave a half-hearted tug, but Castiel didn't let go. Simply turned her hand over to reveal her bloody palm.

He touched his fingers to the cuts on her hand and they faded to nothing before her eyes. Her palm warmed and sizzled with sensation for a second, not unpleasant, and her breath caught in her throat. The pain in her shoulder melted away, the blood in her mouth disappeared. The relief was overwhelming and she had the urge to lean into him, let him cradle her.

Castiel's brow furrowed with effort and she wondered just how unpleasant it was for him to touch her. The nice feelings died, her reality rushing back up to smack her in the face.

 _Angel, demon._

"Sorry," she mumbled, cheeks burning hot. "I mean, thanks."

Ruby pulled her arm away, but Castiel caught it. She flicked her eyes to meet his baby blues. It wasn't fair how pretty they were, she decided, how deep and endless. How easy it would be to lose herself in them.

"Ruby," he said, and damn it, she wanted him to say her name over and over again. "I came here for you."

"I said thanks," she whispered, but it lacked her usual edge. His closeness sent her heart rate into overdrive. She needed to get out of here, but couldn't seem to make her limbs move, pinned under his blue, blue gaze.

"No, I…" He touched his fingers to her bandaged wrist. "I came to Earth, for you. I just did not realize it at the time. Now, I do."

Ruby swallowed. But this was wrong, wasn't it? Wasn't it supposed to be? Her tattoo had come in black and hot and painful, and she was a demon and he was an angel. She couldn't stop repeating those facts because it shouldn't have happened, they shouldn't be here like this, she shouldn't want him or care about him or…

Or…

Maybe the universe _hadn't_ actually fucked up after all.

Castiel tenderly undid the bandages, unraveling them as easily as he'd unraveled her resolve. He let the cloth fall to the floor and Ruby stared, cold ripples of shock skittering across her bones.

 _Castiel_ , her wrist read. In brilliant, shining blue.

He brought his wrist up beside hers, sliding his sleeve back to show _Ruby_ in magnificent, glimmering red.

"Oh," she breathed, completely at a loss.

It still made no sense, it was still impossible and insane, but her questions and objections finally dissolved into the background. Castiel's human face watched her uncertainly, but his angel one was full of understanding and longing—the same kind of longing that the scrap of humanity inside her called out for.

She could see then, somehow, that she fit like a puzzle piece into him. A yin and yang, opposing forces that merged into something new and strange and stunning. And right.

"Well, shit." Ruby smiled, and so did Castiel.

 **-end-**


End file.
